Knitting machine encoder

ABSTRACT

An improved knitting machine includes an encoder which provides signals which vary with variations in the relative position of a needle cylinder and associated feeders. The encoder includes code tracks for providing binary coded needle count signals, feeder count signals, and revolution count signals. A control system receives these binary coded signals and effects the knitting of a selected one of a plurality of patterns. A pattern selector switch is operable to vary the selected pattern.

United States Patent [191 Schuman Aug. 27, 1974 1 KNITTING MACHINEENCODER [75] Inventor: Ralph H. Schuman, Euclid, Ohio [73] Assignee: TheWarner and Swasey Company,

Cuyahoga County, Ohio [22] Filed: Oct. 27, 1971 [21 Appl. No.: 192,984

[52] US. Cl 613/50 R, 250/210, 250/233 [51] int. Cl D041) 15/78 [58]Field of Search... 66/50 R, 50 A, 50 B, 154 A,

[56] References Cited UNITED STATES PATENTS 1l/1965 Frank 250/210 X3,218,626 11/1965 Schuman 250/210 X 3,487,400 12/1969 Ludewig, Jr. eta1. 250/233 X FOREIGN PATENTS OR APPLICATIONS 1,961,102 9/1971 Germany66/50 R 1,521,451 3/1968 France 66/50 R 1,522,413 3/1968 France 66/50 R1,930,522 1/1970 Germany 66/154 A 1,961,021 6/1971 Germany 66/50 R1,194,731 6/ 1970 Great Britain 66/25 Primary ExaminerWm. CarterReynolds ABSTRACT An improved knitting machine includes an encoder whichprovides signals which vary with variations in the relative position ofa needle cylinder and associated feeders. The encoder includes codetracks for providing binary coded needle count signals, feeder countsignals, and revolution count signals. A control system receives thesebinary coded signals and effects the knitting of a selected one of aplurality of patterns. A pattern selector switch is operable to vary theselected pattern.

5 Claims, 7 Drawing Figures PATENIE U A1182 7 I974 SIlEHlBF 5 PAIENTEUAUG 2 71974 smears Y KNITTING MACHINE ENCODER BACKGROUND OF THEINVENTION The present invention pertains generally to code converters,and more particularly to optical shaft encoders.

Optical shaft encoders have been known and used in a variety ofapplications for several years. The most common use of optical shaftencoders is to provide digital position feedback signals forservom'echanism positioning systems, or to provide digital positionsignals for a digital position readout and display system.

Most optical shaft encoders generate binary arithmetic outputs or Graycode outputs. There are also encoders that generate output signals thatrepresent some mathematical function of the input shaft rotation, e.g.the sine of the angle of rotation. None of the known encoders, however,were suitable for providing the required positional signals for anelectronically controlled circular knitting machine.

The knitting machine control system with which the present encoder isintended to operate is described in application Ser. No. 193,047 filedOct. 27, 1971 in the name of Paul Christiansen entitled Knitting MachineControls and assigned to the assignee of the present application.Briefly, the control provides means for assembling pattern data in amemory device, such as a magnetic disc, means for retrieving the storedinformation from memory, and means for directing it to the properelectromagnetic acutators at the several feeders to cause the properneedles to knit or non-knit as required to knit the pattern representedby the stored pattern data. The encoder of the present inventionprovides the knitting machine control with position signals to enablethe control to retrieve the proper portion of pattern data from memoryat the proper time and direct it to the proper feeders and actuators.These signals represent the rotational position of the knitting machinewith respect to a reference position in terms of needle distances, and aplurality of multiple needle distances including an echelon, a byte, anda feeder distance. Knitting machine revolutions are also represented,and the number of revolutions uniquely represented between appearancesof reference position is selectable to accommodate a plurality ofpattern types and heights.

Therefore, it is an object of the present invention to provide animproved optical shaft encoder for use with circular knitting machines.

It is a further object of the present invention to provide an encoder togenerate signals representative of knitting machine position in terms ofneedle distances and multiple needle distances.

It is a still further object of the present invention to provide anencoder to generate signals representative of knitting machinerevolutions, and to provide means for selecting the number ofrevolutions uniquely represented between appearances of the referenceposition.

These and other objects and advantages of the present invention willbecome apparent as the detailed description proceeds, reference beingmade to the attached drawings and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified elevation viewof a circular knitting machine, partially cutaway to reveal the knittedhose and take-down mechanism.

FIG. 2 is a generalized block diagram showing how the encoder of thepresent invention fits into the control system.

FIG. is an illustration ofa code disc having a plurality of concentriccode tracks comprising transparent and opaque code zones.

FIG. 4 is a developed view of a portion of the fine code disc showingits origin.

FIG. 5 is a logic circuit diagram illustrating how signals from thephotocells reading the fine disc are operated upon logically to producethe desired binary code.

FIG. 6 is a developed view of a portion of the coarse code disc showingits origin.

FIG. 7 is a logic circuit diagram illustrating how the signals from thephotocells reading the coarse code disc and some of the signals fromphotocells reading the coarse code disc are operated upon logically toproduce the desired binary code.

DESCRIPTION OF THE PREFERRED EMBODIMENT The general relationshipsbetween the positional signals required by the control described inapplication Ser. No. 19,047 filed Oct. 27, 1971 by Paul Christiansen andentitled Knitting Machine Controls and the relationships with othercircular knitting machines are somewhat similar, but will differ indetail according to the specific geometry of each knitting machine andother factors. For example, the knitting machine controls of theChristiansen application require an indication of actuator or needlecount, feeder count and revolution count as knitting progresses.However, one knitting machine may have 48 feeders and 2,400 needles,while another may have 36 feeders and 1,728 needles. One may knit 12repeats of a pattern while the other knits nine repeats of the same sizepattern. Because of these differences, no standard binary arithmetic orGray code encoder can readily be used to generate the required signals.Nor, may an encoder made according to the present invention for oneknitting machine generally be usable with another knitting machinehaving a different number of needles and feeders. Another encoder,however, embodying the subject matter of the present invention could beconstructed to accommodate the specific geometry of the otherknittingmachine.

To illustrate the encoder of the present invention, one specificembodiment will be shown and described for use with a circular knittingmachine having 1,872 needles and 36 feeders. As the knitting machinecylinder turns, each of the needles is sequentially brought intooperative relationship with each of the feeders. At each feeder, eachneedle must knit or non-knit. That is, it must move up to the knitposition and take a new loop or stay below the knit position and notcreate a new loop. The term knit as used herein will include tuckwherein a new loop is created without throwing off the old loop.

At each feeder there are cam tracks that cooperate with projecting cambutts on needle jacks and selector jacks to lift the needles to therequired height. Needles are selected to knit or non-knit byelectromagnetic actuators that either interfere with a selector butt ona selector jack, causing its cam butt to enter the non-knit cam track,or do not interfere with the selector butt so that the cam butt entersthe knit cam track. Thus, because there are 1,872 needles and 36 feedersin the illustrative knitting machine, 36 X 1872 or 67,392 knit andnon-knit commands must be supplied to the actuators each revolution ofthe knitting machine. If the illustrative knitting machine were operatedat 24 revolutions per minute, then the actuators would require about27,000 knit and non-knit commands per second. Although this is not ahigh data transmission rate for electronic digital computers, it isquite a high data transmission rate to interface to a mechanicalapparatus such as a knitting machine. The encoder of the presentinvention permits handling the necessary knit and non-knit informationat the required data transmission rates with considerably fewerelectronic manipulations, and therefore greater economy, than couldotherwise be achieved.

As described in more detail in application Ser. No. 193,047 referred toabove, pattern data is stored on nine tracks of a magnetic disc. Eachtrack is divided into four zones. One zone stores all the pattern datafor one feeder for a complete pattern. An arbitrary pattern size of 208stitches wide by 216 stitch rows high was selected for use on theillustrative knitting machine. Thus, because there are 1,872 needlesaround the cylinder, the pattern will be knitted nine times around thecircumference of the finished knitted tube. The number of revolutionsrequired to knit the 216 stitch rows of pattern height, however, willdepend upon the type of pattern being knitted. For example, three-colorplain pattern requires three feeders per stitch row. Therefore, theillustrative machine will knit l2 stitch rows per revolution and require18 revolutions to knit 216 stitch rows. For a pattern requiring only twofeeders per stitch row, the illustrative machine will knit 18 stitchrows per revolution and would require only 12 revolutions to knit 216stitch rows.

In both the examples given above, the pattern would be knitted ninetimes during the required number of revolutions. This is true for allpatterns 208 stitches wide knitted on the illustrative machine. Or,stated in another way, the stored pattern data will be used nine timesduring the required number of revolutions to knit 216 stitch rows.

The four zones of each data track on the magnetic disc are divided intosectors such that a sector contains all the knitting data required forone feeder for one full stitch row of the pattern. Since a pattern widthof 208 stitches has been selected, each sector must contain 208 bits ofdata. Because a feeder knits on the same stitch row of the pattern forone full revolution of the knitting machine, which is nine repeats ofthe pattern in the present embodiment, a new sector address is requiredonly once per revolution. The information from the sector, however, willbe used nine times during the revolution. Revolution count and sectoraddress are provided by the encoder and its associated translatorcircuitry.

Because of operating speed limitations of the electromechanicalactuators, the task of steering the needles at each feeder is dividedamong 13 actuators. In this manner, each actuator steers only every 13thneedle. Thus, signals are required for directing the knit and non-knitinformation to the proper actuator at each feeder. These signals arealso provided by the present encoder and its associated translatorcircuitry.

Because a continuous flow of knit and non-knit information is requiredby each feeder and because information is retrieved from the disc in adiscontinuous manner, an interface is required between the disc and eachfeeder. This interface, in the present embodiment, may include two 26bit shift registers per feeder. While the information is being read outof one of the shift registers, information is located on the disc andloaded into the other shift register. Therefore, by switching back andforth between its two associated shift registers. a feeder receives acontinuous flow of patterning information. In an alternative system, asingle 208 bit shift register is provided for each feeder and a 208 bitbuffer shift register provides the time interface between the disc andall the feeder shift registers. In the first system the 26 bits requiredto load each shift register are taken from the 26-bit bytes ofinformation on the disc. In order to retrieve these bytes, a byteaddress is required in addition to the sector address. The byteaddresses are provided by the present encoder and its associatedtranslator circuitry. In the second system, byte addresses are notrequired. Instead, the 208 bits in each feeder shift register arerecirculated for a full knitting machine revolution.

Two-color plain patterns, and one-color tuck patterns, require twofeeders per stitch row. Three-color plain patterns, and oneand two-colorblister patterns require three feeders per stitch row. Four-color plainpatterns and three-color blister patterns require four feeders perstitch row. An arbitrary pattern height of 216 stitch rows then requirestwelve revolutions, 18 revolutions, and 24 revolutions for two, three,and four feeder-per-stitch row patterns, respectively. In order toselectively knit two, three, or four feeder-per-stitch row patterns, theencoder signals must recycle to the beginning after 12, 18 or 24 machinerevolutions. To knit a two-feeder-per-stitch row pattern 108 stitch rowshigh, the encoder signals must recycle after six revolutions. Othercombinations may also be desired. To avoid prolixity of description, thecontrols of the above identified Christenson application Ser. No.193,047 will not be set forth in detail herein. However, it should beunderstood that the disclosure of this application is fully incorporatedherein by this and other references thereto.

FIG. 1 is a diagrammatic illustration of a circular knitting machine 10partially cut away to show the finished knitted tube 11 and thetake-down mechanism 12. A creel structure 13 supports spools of yarn 14to be knitted. The yarn passes through tensioning means 15 and stopmotions l6 and 17 to feeder blocks located circumferentially around theknitting machine at 18. A large ring gear 21 mounted to the lowerportion of the knitting machine or needle cylinder drives a pinion gear22 mounted on the input shaft of optical shaft encoder 25 which isaffixed to the frame of knitting machine 10 in any suitable manner. Asthe knitting machine cylinder rotates, ring gear 21 drives pinion gear22 to rotate the input shaft of encoder 25.

Within encoder 25 are two code discs, a fine code disc 27 (FIGS. 3 and4) and a coarse code disc 28 (FIG. 6). Fine code disc 27 is mounted forrotation on a shaft that is gear coupled to input shaft 26 such thatfine code disc .27 rotates three full revolutions for each rotation ofthe knitting machine needle cylinder. Coarse code disc 28 is mounted forrotation on a shaft that is gear coupled to the fine code disc shaftsuch that coarse code disc 28 rotates one full revolution for each 216fine code disc revolution, which is one full revolution for each 72knitting machine cylinder revolutions.

Each of the encoder discs 27, 28 have a plurality of code tracks withwhich a plurality of photocells cooperate to provide a plurality ofbinary coded electrical signals. These signals may be used directly, orbe operated upon logically to provide further binary coded signals, toprovide the necessary synchronizing and position indicating informationfor the knitting machine control. It is not necessary to describe indetail here the relationship between encoder discs, light sources, andphotocells, because these details are well known in the art. Forexample, see US. Pat. No. 3,218,626 issued Nov. 16, 1965 to Ralph H.Schuman and assigned to the assignee of the present invention.

FIG. 2 is included to illustrate generally where and how encoder 25 fitsinto and cooperates with the overall knitting machine and control. Thecircular knitting machine, including its drive, feeders, cylinders,etc., is represented by the block 31. The mechanical coupling betweenthe knitting machine cylinder and encoder 25, including gears 21 and 22,is represented by block 32. Many of the binary electrical signalsgenerated by encoder 25 are operated upon logically by translatorcircuitry 33 to provide derived signals. Both the derived signals andsignals from encoder 25 are used by a plurality of feeder controls 34 toretrieve the proper knitting data from memory means, such as a magneticdisc, and provide the proper knit and non-knit signals to the feederactuators in block 31. It will be recognized that the immediatelyforegoing description of how the encoder of the present invention fitsinto the overall control is very abbreviated. The overall control isfully described in Paul Christiansens Application Ser. No. 193,047 filedOct. 24, 1971, entitled Knitting Machine Controls and referred to above.

FIGS. 3 and 4 show the arrangement of the code tracks and photocells ofthe first or fine disc 27. The presence of crosshatching indicates anarea of a transparent characteristic that will permit light to pass andilluminate a photocell to generate a logic one signal. The absence ofcrosshatching represents an area of an opaque characteristic that willprevent light from illuminating a photocell to thereby generate a logiczero. Because the fine disc 27 makes one revolution for each one-thirdrevolution of the knitting machine, it must resolve 1,872 3 or 624 partsper revolution to provide a change in signal each time the needles areadvanced one needle position during a revolution of the needle cylinder.This is achieved by dividing the finest code track 40 into 312 opaqueand 312 transparent zones of equal size and alternately located aroundthe code track with each of the opaque and transparent zonescorresponding to a needle position. The code track 40 is utilized toprovide needle signals which vary in response to relative movementbetween the needle cylinder and feeders by an extent corresponding tothe spacing of adjacent needles.

A pair of photocells 41, 42 are connected in a pushpull relationship andpositioned 180 of a needle position out of phase with respect to finecode track 40 to read the fine code track through mask slits 43 whichhave a width that is approximately one-third the tangential dimension ofeither an opaque or transparent code zone. This provides a signal which,after amplification, is considerably more precise than onetenth of acode zone, or, related to the knitting machine, onetenth of a needledistance. The fine code track photocell outputs are labeled A+ and A.These outputs are fed in push-pull to an amplifier 44 (FIG. 5) toproduce a signal A which is at logic one when photocell 41 isilluminated. Amplifier 44 also produces a signal A, the complement ofsignal A. Signals A and A are connected respectively to monostablemultivibrators 47 and 48. Monostable multivibrator 47 produces a shortpulse output each time signal A changes from logic one to logic zero andmonostable multivibrator 48 produces a short pulse output each timesignal A changes from logic one to logic zero. The outputs of monostablemultivibrator 47 and 48 are combined by or gate 49 to produce on line 50one pulse each time the knitting machine has moved one needle position.These pulses may be used to transfer patterning data from feeder controlstorage to the actuators. An additional monostable multivibrator 51which generates a short pulse output each time the signal on line 50changes from one to zero may be used to shift feeder control shiftregisters in timed relationship with rotation of the needle cylinder ina manner more fully described in the aforementioned Christiansenapplication Ser. No. I93,047. In order to provide an enabling signal toeach of the thirteen actuators at each feeder, it is necessary toprovide an actuator or needle count number to indicate which of thethirteen needles in each echelon is to be steered next. To produce thisindication, a second code track 55 is provided on the fine disc 27. Thiscode track 55 is divided into 24 transparent and 24 opaque code zones,each having a tangential length substantially equal to 13 finest codetrack 40 code zones (48 X 13 624). Thirteen photocells 56 are arrangedto read the second code track in a staggered or phase displaced mannerto provide 13 outputs that are labeled B, C, D, E, F, G, H, I, J, K, L,M, and N in FIGS. 4 and 5.

The signals from the thirteen photocells 56 are combined logicallyaccording to the Boolean Algebra equa-.

tions of Table I to provide the actuator enabling signals E0 E12corresponding to the number of an actuator to be enabled for activationin accordance with a pattern signal from a suitable memory device (notshown but fully described in the aforementioned Christiansenapplication). Since each opaque and transparent zone of the code track55 corresponds to 13 needles and associated actuators, any one of whichmay require activation to knit a selected pattern, thirteen enablingsignals E0 E12 are provided for each of the opaque and transparent zonesof the code track 55. The actual decoding circuitry is illustrated inFIG. 5 wherein each of the photocells 56 is connected to an inverter 57to produce the signals B, C, I E, F, G, FLT, T, KI, K1 and N as well asB, C, D, E, F, G, H, I, J, K, L, M, and N.

To produce each of the enabling signals E0 E12 for each transparent andopaque zone of the code track 55, the photocells 56 are paired by thelogic circuitry of FIG. 5. When the leading photocell of a pair isadjacent an opaque zone and the trailing cell is adjacent a transparentzone an enabling signal is produced. In addition, when the leadingphotocell of a pair is adjacent a transparent zone and the trailing cellis adjacent an opaque zone another enabling signal is produced. Thus,for the pair of cells B and M, an enable signal E is produced bycombining KB, and M in an and gate 58, combining A, B, and M in an andgate 59, and combining the outputs of and gates 58 and 59 in or gate 60.This produced E0 in accc dance with the Bo olean equation E0 AB M A B M.Similarly A, C, N, A, C, and N are combined in and gates 61 and 62 andor gate 63 to produce E1 according to the Boolean equation E1 A C N KCN. Each of the remaining enable signals E2 E12 are produced similarly inaccordance with the Boolean equations of Table l, the circuitry forproducing E2 Ell being omitted to avoid unnecessary prolixity.

E11=AKM+AKM E12 A L N A t N Because in the aforementioned Christiansenapplication there are 26 bits in a byte in the selected pattern dataformat, it is necessary to provide 26 discrete steering signals totransfer each pattern data bit from a 26 bit shift register to one ofthirteen actuators. One manner of accomplishing this is to provide anadditional signal that is at logic one during alternate echelons ofneedles. For this reason, a third code track 64 is provided on fine disc27 having alternate transparent and opaque areas each having atangential length substantially equal to 26 finest code track 40 codezones. Photocells 65 are positioned 90, or 6 1/2 fine code track zonesout of phase to read code track 64 to provide outputs that ge labeled 0and P. Inverters 66 produce the signals O and 1 Should it be desired tokeep track of echelons of needles, e.g. whether the echelon is even orodd, such a signal may be provided by associating even echelons withopaque zones of the code track 55 and odd echelons with transparentzones of the code track 55. This may be accomplished by logicallycombining signals A, B, L, M, and N according to the Boolean equation,EEl A B M L N A I: N with and gates 67, 68, 69, and or gate 70. Thisproduces a logic one when the echelon is odd and a logic zero when theechelon is even. Similarly, a byte signal may be produced by the logicalcombinationEBI=ABM+NO+MP+ALNwithand gates 71 74 and or gate 75. SignalEBl will be at logic zero when the byte number is even and at logic onewhen the byte number is odd, and may be used to steer bytes read fromthe disc to the proper one of two feeder shift registers. The bytesignal is also used in determining the feeder number as will bedescribed below.

During operation of the knitting machine 10, pattern data for at least aportion of a particular stitch row is transmitted from a memory disc tocontrols for a feeder of a feeder group which is knitting thisparticular stitch row. The pattern data for any one feeder of a feedergroup may be different than the pattern data for any other feeder in thefeeder group. Since different stitch rows of a pattern are knitted byeach feeder group on consecutive revolutions of the needle cylinder, thepattern data for any one feeder may be different on differentrevolutions of the needle cylinder. In addition, dur' ing any onerevolution of the needle cylinder from feeder 0 to feeder 35, the feedergroups ahead of a first needle on the cylinder and the pattern changepoint will be completing the knitting of a stitch row corresponding tothe preceeding revolution of the needle cylinder while the feeder groupsbehind the first needle and after the pattern change point will beknitting a stitch row corresponding to the present revolution of theneedle cylinder. It should be understood that the beginning and endingpoints of a stitch row are displaced longitudinally along a generallycylinderical tube of knitted material by a number of stitch rowscorresponding to the number of feeder groups. Therefore, the patternchange point extends linearly along the tube of knitted material.

A feeder count number which is indicative of the feeder in which thefirst needle on the needle cylinder and pattern change point are locatedis transmitted from the translator 33 to the feeder controls 34. Toprovide a feeder number which changes with movement of the patternchange point and of the first needle on the needle cylinder from feeder0 through feeder 35 with each revolution of the needle cylinder, thefine code disc has three additional code tracks 81, 82, and 83. Note thechange of scale in FIG. 4 between code tracks 64 and 81. Code track 81is equally divided into six opaque and six transparent code zones.Because the fine code disc rotates one revolution for each one-thirdrevolution of the knitting machine, and since there are 36 feeders and52 needles per feeder on the knitting machine, one code zone on codetrack 81 corresponds to one feeder on the knitting machine and 52 zonesof code track 40. Code track 82 is divided into two transparent and twoopaque code zones, the opaque zones being twice as long as thetransparent zones and alternately located with the transparent zones asshown in FIG. 4. Thus, an opaque zone of code track 82 corresponds tofour feeders and a transparent zone corresponds to two feeders. Codetrack 83 is divided into two equal code zones, one transparent and oneopaque. Each of the zones of code track 83 corresponds to six feeders.Lead and lag photocells 84 are positioned as shown in FIG. 4 andcooperate with code tracks 81, 82, and 83 to provide binary code signalsFlD, FIG, F2D, F2G, F4D, F4G, F6D, and F6G.

The lead photocell (D) of each photocell pair is located so that itreads ahead of the actual transition point and each lag photocell (G) islocated so that it reads behind the actual transition point. The bytesignal (EBl) is utilized to switch between lead and lag photocells 84.Lead-lag switching is accomplished by and gates 84D, 84G, 85D, 85G, 86D,866, and 87D, 876, and or gates 88, 89, 90, and 91, connected as shownin FIG. 5. Signal EBl is directly connected to one input of each andgate 84G, 85G, 86G, and 87G, to enable those gates when EBl is at thelogic one level during odd bytes. Signal EBl is connected to one inputof each and gate 84D, 85D, 86D, and 87D, through an inverter 92 toenable those gates when B81 is at the logic zero level during evenbytes. Because the byte signal depends on the A signal for its accuracy,and because the A signal is accurate to approximately one-tenth needleposition, use of the byte signal to control the lead-lag switching onphotocells 84 provides binary code signals EF1, EF2, EF4, and EF6,weighted 1, 2, 4, and 6, and

indicating feeder numbers from thru 11 with an accuracy of one-tenthneedle position. I

In order to provide feeder numbers 0 35 on each needle cylinderrevolution, feeder numbers 0 11 are generated three times. That is,during a first revolution of the fine code disc 27, code tracks 81, 82,and 83 are decoded to indicate feeders 0 11. The next revolution theyare decoded to indicate feeders l2 23. During the third revolution theyare decoded to indicate feeders 24 35. The coarse code disc 28 isassociated with the fine code disc 27 to provide the necessaryinformation as to which series of feeder numbers is being provided atany given time. Thus, the code tracks 81, 82 and 83 are utilized toprovide coded feeder signals which vary in response to relative movementbetween the needle cylinder and feeders by an extent which is a functionof the spacing of adjacent feeders. These coded signals are indicativeof the feeder with which the first needle is associated.

Whether code tracks 81, 82, and 83 should be decoded as feeders 0 11, 1223, or 24 35, is determined by signals generated by code tracks on thecoarse code disc 28 that is coupled to the fine code disc 27 by gearmeans giving a 216:1 gear ratio such that coarse code disc 28 rotatesone time for each 216 revolutions of the fine code disc. This means thatthe coarse code disc will rotate once for each 72 revolutions of theknitting machine. The coarse code disc 28 has seven code tracksconcentrically arranged similarly to the code tracks of fine code disc27 shown in FIG. 3. These are identified in order of decreasing diameterby reference numerals 93 99 and are illustrated in a developed view inFIG. 6. Code track 83 of fine disc 27 is shown at the top of FIG. 6 toillustrate the relationship between code discs 27 and 28. As waspreviously mentioned, each of the zones of code track 83 corresponds tosix feeders. The numerals immediately below code track 83 in FIG. 6indicate revolutions of the needle cylinder, each of which correspondsto three revolutions of the fine disc 27. Note the scale change betweencode tracks 96 and 97.

Signals indicative of which of the three revolutions is being made bythe fine code disc 27 are provided by four photocells 101 arranged intwo lead-lag pairs to read code track 93 and provide signals F12D, F12G,F24D, and F24G. As shown in FIG. 7, leadlag switching is accomplished byand gates 103 and or gates 104. And gates 103 are alternately enabled toselect either the lead or lag signals by means of signal EF6 beingdirectly connected with the lag gates and connected to the lead gatesthrough an inverter 105. Thus, when transparent zones (crosshatched) oncode track 93 are being read and signal EF6 is at the logic one level,signals F126 and F240 are enabled. When opaque zones (not cross-hatched)on code track 93 are being read and signal EF6 is at the logic zerolevel and signals F12D and F24D are enabled.

When code tracks 81, 82 and 83 are to be decoded as feeders 0 11 thegated photocells 101 are reading opaque zones of code track 93 and theenabled signals EF12 and EF24 are at logic level zero. During continuedrotation of the needle cylinder certain of the photocells 101 readtransparent zones of code track 93 and the code tracks 81, 82 and 83 aredecoded as feeders 12 23. During this time signal EF12 is at logic levelone while EF24 remains at logic level zero. Upon still further rotationof the needle cylinder, code tracks 81, 82 and 83 are decoded as feeders24 35 and signal EF12 returns to logic level zero while signal EF24 isat logic level one. Thus both signals EF12 and EF24 remain at logiclevel zero for 24 consecutive feeder numbers and are at logic level onefor 12 consecutive feeder numbers.

To enable signal EF12 to remain at logic level zero for feeder numbers24 35 during one revolution of the needle cylinder and for theimmediately succeeding feeder numbers 0 11 on the next revolution of theneedle cylinder, code track 93 has 72 opaque zones which are read byphotocells F12D and F12G during feeder numbers 24 35 of one needlecylinder revolution and feeder numbers 0 11 of the next needle cylinderrevolution. However, signal EF12 is at logic one level during feedernumbers 12 23 of each needle cylinder revolution. Accordingly, codetrack 93 has 72 transparent zones (shown crosshatched in FIG. 6) whichare read by the photocells F12D and F12G during feeder numbers 12 23.The transparent zones of code track 93 are one half as long as theopaque zones.

The signal EF24 remains at logic level zero during feeder numbers 0 23and is at logic level one during feeder numbers 24 35. Thus, signal EF24switches to logic level one as signal EF12 switches from logic level oneto logic level zero. Accordingly, photocells F24D and F246 read atransparent zone of code track 93 immediately after it is read by thephotocells F12D and F12G.

The signals produced by photocells 101 may be considered as addersignals for combining with the EF1, EF2, EF4, and EF6 signals to producea binary code weighted 1, 2, 4, 6, 12, 24. The truth table for thefeeder numbers is as follows:

COARSE DISC FINE DISC Feeder No. EF24 EFl2 EF6 EF4 EF2 EH 0 O 0 O 0 V 0O l 0 O 0 0 0 l 2 0 0 0 O l 0 3 O 0 0 0 l l 4 O 0 0 l O 0 5 0 O O l 0 l6 O 0 l 0 O 0 7 0 0 l 0 0 l 8 0 0 l 0 l 0 9 0 0 l O l 1 l0 0 0 l l O 0 ll 0 O l l 0 1 l2 0 l O 0 0 0 l3 0 l O 0 0 l 14 0 l O O l 0 l5 0 l 0 0 l1 l6 0 1 O l 0 0 l7 0 l 0 l O 1 l8 0 l l 0 0 0 l9 0 l l O O l 20 0 l l 0l O 21 O l l O l l 22 0 l l l 0 0 23 O l l l O .l 24 I 0 0 O 0 0 25 l 00 0 0 l 26 l O O 0 l O 27 l 0 0 0 l l 28 l 0 O l 0 0 29 l 0 O I O l 30 l0 l 0 0 0 31 l 0 l O 0 l 32 l 0 l 0 I O 33 l 0 l 0 l l -Continued COARSEDISC FINE DISC Feeder No. EF24 EFl2 EF6 EF4 EFZ EFI 34 l l l 0 0 35 l 01 l 0 1 By proper digital arithmetic techniques, these signals may betranslated to feeder count numbers in any desired code, e. g. normalbinary weighted 1, 2, 4, 8, 16, etc. FIG. 7 shows how signals EFl EF24may be translated to normal binary by the use of a S-stage full binaryadder or register means 111 having carry-in and carry-out capacity.Adder 111 is arranged to add two normal binary numbers, A and B, plus acarry-in bit at C-in, and produce their sum 5. The electrical signalsrepresenting number A are connected to terminals Al A16 and thoserepresenting number B to terminals B1 B16, the terminal referencenumerals also indicating the numerical weight of their digit signals.The signals representing the sum appear at terminals S1 S16 and atcarry-out terminal C-out. EFl, EF2, and EF4 are directly connected toA1, A2, and A4, respectively. EF6, weighted 6, is connected to Gin andB1 via an and gate 112, and thence to B4 via one input of or gate 113.

When and gate 112 is enabled, a logic one on EF6 will cause logic onesto appear at C-in, B1, and B4 contributing six toward the sum S. EF12,weighted 12, is connected to B8 via an and gate 115, and thence to B4via the other input of or gate 113. Thus, when and gate 115 is enabled,a logic one on EF12 will cause logic ones to appear at B4 and B8,contributing twelve toward the sum S. EF6 and EF12 are also connected toan and gate 116, the output of which is connected to B2 and B16. Thus,when EF6 and EF12 are both at logic one, logic ones appear at B2 andB16, contributing 18 toward the sum S. The output of and gate 116 isalso inverted by an inverter 117, the output of which provides theenabling signal for and gates 112 and 115. Thus, when EF6 and EF12 areboth at logic one, and gates 112 and 115 prevent logic ones fromappearing at C-in, B1, B4, and B8. EF24, weighted 24, is directlyconnected to A8 and A16, and therefore, a logic one on EF24 contributes24 to the sum S. The sum appearing at terminals S1 S16 and Com indicatesthe knitting machine feeder count number in normal binary arithmetic.The feeder count number digit signals are designated F1, F2, F4, F8,F16, and F32, the numerical portion of the designation indicating thenumerical weighting of the digit signal.

The feeder count number is transmitted from the translator 33 to thefeeder controls 34 and is utilized to provide a feeder offset numberwhich shifts from logic level zero to logic level one immediately beforethe pattern change point enters a feeder. The operation of the feedercontrols 34 is not, per se, a part of the present invention andtherefore has not been fully described. However, the operation of thefeeder controls is fully set forth in the aforementioned Christiansenapplication.

It is contemplated that the knitting machine will be utilized to knitmany different types of patterns, such as two, three or four color plainpatterns or one, two or three color blister patterns. In order to enablethe machine 10 to knit these different patterns, the 36 feeders'areassociated in a known manner in groups of either two, three or fourfeeders, depending upon the pattern to be knitted. Assuming a constantpattern of 216 stitch rows, the number of revolutions required to knit apattern will vary depending upon the number of feeders in each feedergroup. Thus, for a pattern having one feeder in each feeder group, sixrevolutions of the needle cylinder are required to knit the pattern. Fora pattern having two feeders in each of eighteen feeder groups, 12revolutions of the needle cylinder are required to knit the pattern.Similarly, a three feeder group pattern is knitted in 18 cylinderrevolutions and a four feeder group pattern is knitted in 24 cylinderrevolutions.

Once a pattern has been knitted during the requisite number of needlecylinder revolutions, the pattern is repeated as the needle cylindercontinues to rotate. To facilitate for this repetitive knitting of thepattern, the signals from the encoder 25 are repeated each time theneedle cylinder rotates through the requisite number of revolutions.Thus, the signals from the encoder 25 are repeated after every sixrevolutions when one feeder is used in each feeder group to knit a 216stitch row pattern. Similarly, the signals from the encoder 25 arerepeated after twelve revolutions for a pattern requiring two feedersper group, after 18 revolutions for a pattern requiring three feedersper group, and after 24 revolutions for a pattern requiring four feedersper group.

To enable the signals from the encoder to be repeated in the number ofrevolutions corresponding to the selected pattern, photocells 120, 121,122, 123, 124, and 125 cooperate with code tracks 94, 95, 96, 97, 98,and 99 to provide revolution count signals which repeat after eithersix, l2, 18 or 24 cylinder revolutions. A selector switch 133 (FIG. 7)is provided to enable the cycling of the revolution count to be matchedwith a selected pattern.

To provide repetitive revolution count signals, code track 94 is equallydivided into 36 transparent and 36 opaque code zones of equal tangentiallength alternately located about the code track. Lead and lag photocellsreading this code track are switched by the EF6 signal in the samemanner as the signals from photocells 101 to produce one change of asignal ER1 for each revolution of the knitting machine. Thus, the ER1signal functions as the units digit signal for a binary coded set ofsignals indicating revolution number. The additional binary coded digitsignals for indicating revolution number are generated by code tracks 9599 and photocells 121 125 as shown in FIGS. 6 and 7. Each of thephotocells 121 125 are arranged in leadlag pairs to produce signals R2D,R2G, R4D, R6D, R66, R6/3D, R6/3G, Rl2/3D, R12/3G, R12D, R120, R24D,R246. These signals are connected to and gates 128 that are switched bythe ER1 signal in the same manner that the EF6 signal switches thesignals from photocells 101 and 120. Or gates 129 combine the signalsfrom and gate pairs. Since the ER1 signal is switched by the EF6 signal,which in turn is switched by the A signal, one-tenth needle positionaccuracy is maintained in resulting revolution number signals ER1, ER2,ER6, ERG/3, ERl2/3, and ER12. The truth table for these signals is asfollows:

Switched by ER6 ER24 ERl2 Needle Lead- Cylinder Lag Rev. ER48 Lead LagER6/3 ERG Switched by ER! ER4 ER2 ERl CCCOOOO U (I 1) I) ll! 0 O l l l)0 l2 0 0 I] 0 0 To provide a revolution count which is cyclic in sixrevolutions to knit a 216 stitch row pattern requiring only one feederper group, the selector switch 133 (FIG. 7) is set to position X6. Whenthe selector switch is in this position, only signals ER], ERZ and ER4are utilized to repetitively count from zero to five. Thus, on thesixth, 12th, 18th, etc., needle cylinder revolutions the signals ERl,ER2 and ER4 are logically combined to indicate revolution zero when theselector switch 133 is set to position X6.

A revolution count which is cyclic in 12 revolutions is necessary toknit a 216 stitch row pattern requiring two feeders per group. Toaccomplish this the selector switch 133 is set to position X12 andsignals ERl, ER2,

ER4 and ER6 are utilized to repetitively count from zero to eleven.

When the selected pattern requires three feeders per group, the selectorswitch 133 is set to position 18X to enable signals ERl, ER2, ER4, ER6/3and ER12/3 to be combined to provide a revolution count which is cyclicin eighteen revolutions. It should be noted that the ER6/3 signal wasutilized rather than the ER6 signal. This is because repetitive countingto eighteen requires that the signal given a weight of six must be atlogic level zero for cylinder revolutions l2 17 during one countingcycle and remain at level zero for revolutions 5 of the next followingcounting cycle. Since the ER6 signal must change logic levels every sixrevolutions to enable this signal to be used for a revolution countwhich is cyclic in 12 revolutions, this signal is unsatisfactory for usein providing a revolution count. which is cyclic in 18 revolutions. Itshould likewise be noted that the ER12/3 signal was utilized rather thanthe ER12 signal. This is because repetitive counting to 18 requires thata signal given the weight of 12 must be at a logic one for cylinderrevolutions 12-17 during each counting cycle, and the ER12 signal is ata logic zero during a needed portion of the entire 0-71 cylinderrevolution counting capacity of the coarse disc, i.e., the ER12 signalis at a logic level zero during needle cylinder revolutions -35 and48-53 as can be seen frqm. t s mitlttablsz Finally, when a 216 stitchrow pattern requiring four feeders per group is to be knitted, theselector switch is set to position X24. This setting of the selectorswitch results in signals ERl, ER2, ER4, ER6 and ER12 being utilized toprovide a revolution count which is cyclic in 24 revolutions.

Referring to FIG. 7, it will be seen that signals ERl, ER2, and ER4 areconnected to the Al, A2, and A4 terminals of a full binary adder orregister means 131 which is identical to and has terminals identifiedthe same as adder 111. A multi-position selector switch 133 has a wipercontact 132 connected to a source of voltage +V which represents a logicone. Each of the terminals of switch 133 may be connected to ground(logic zero) by a resistor 134 to insure that a logic zero appearsthereon whenever the wiper contact 132 is turned to another position.The terminals are designated X6, X12, X18 and X24, the numerical portionof the designation indicating the number of revolutions per patterncycle.

The logic circuitry for gating revolution number signals ERl ER24 isfully described by the circuit diagram of FIG. 7 and therefore need notbe described verbally. Turning switch 133 to its various positionsoperates to enable different combinations of and gates to pair selectedones of signals ER6, ER6/3. ER12/3, and

ER12 to adder 131. Selective translator circuitry for utilizing ER24 andER48 is not shown in FIG. 7, however, the translator circuitryillustrated may be readily extended to encompass those signals. Forexample, ER24 would, via appropriate gating, enabled by an additionalterminal on switch 133, be selectively connected to A8 and A16 of adder131, thereby contributing 24 toward the sum at the proper time. Thus,the code tracks 93-99 cooperate with the associated readers to providecoded revolution signals which vary in response to relative movementbetween the needle cylinder and feeders by an extent which is a functionof one complete revolution of relative movement. These coded revolutionsignals are indicative of the number of revolutions of relative movementwhich have occurred.

By way of illustration, two translator configurations will be describedin detail. First, with switch 133 in the X6 position, only and gates 141and 142 will be enabled by the output of inverter being at logic onebecause the output ofand gate 139 is at logic zero. The output of andgate 139 can be at logic one only when switch 133 is in the X24position. However, because and gates 143, 144, 145, and 146 aredisabled, no signals other than ERl, ER2, and ER4 will reach adder 131.Therfore, the output of adder 131 will be normal binary that counts 0 5and repeats. These revolution signals are associated with the feedercontrols 34 in the manner fully described in the aforementionedChristiansen application to repeat a selected pattern after every sixrevolutions of the needle cylinder.

With switch 133 in the X18 position, as shown in FIG. 7, and gates 144and 145 are enabled to pass the ER6/3 and ER12/3 signals to adder 131.Disabled and gates 143 and 146 prevent the passage of signals ER6 andER12. Signal ER6/3 is connected via and gate 144 and or gate 147 to B2,and thence via or gate 148 to 134. Thus, when ER6/3 is at logic one, B2and B4 are at logic one, contributing six to the adder output.Similarly, signal ER12/3 is connected via and gate 145 and or gate 149to B8, and thence via or gate 148 to B4. Thus, when signal ER12/3 is atlogic one, twelve will be contributed to adder 131 output. Because ER6/3and ER12/3 are never both at logic one at the same time, both signalsmay share the B4 terminal of adder 131.

The output of adder 131 is the revolution number in normal binaryarithmetic. The revolution number digit signals are designated R1, R2,R4, R8, R16, and R32, the numerical portion of the designationindicating the numerical weighting of the digit signal.

Description of how the signals generated by the encoder of the presentinvention are utilized by the knitting machine control in the mannerfully described in Paul Christiansen application Ser. No. 193,047 filedOct. 27, 1971, and entitled Knitting Machine Controls. Suffice it to besaid here that the encoder of the present invention provides electricalsignals necessary for generating data addresses for retrievingpatterning information from a memory, and provides signals for insuringthat the right data reaches the right actuator at the right time. Thosewho are interested in the manner in which the signals from the encoder25 may be utilized to effect operation of a knitting machine arereferred to the aforementioned Christiansen application.

It will be appreciated that the arithmetic base of the encoder of thepresent invention may be altered to suit the requirements of anyparticular circular knitting machine without departure from the spiritor scope of the claims. It should also be understood that although thepresent invention has been described herein in association with aknitting machine of the type in which the needle cylinder rotatesrelative to stationary feeders, the present invention could be utilizedin association with a known type of knitting machine in which thefeeders rotate relative to a stationary needle cylinder. It should alsobe understood that although it is contemplated that the presentinvention can advantageously be used with the knitting machine controlsof the aforementioned Christiansen application, the present inventioncan also be used in conjunction with other knitting machine controlsystems.

Having described a specific preferred embodiment of the invention, thefollowing is claimed:

1. Apparatus for use in a knitting machine having a needle cylinderholding a plurality of needles to which strands of material are fed fromfeeders during relative rotation between the needle cylinder and feedersto knit a predetermined one of a plurality of different patterns theknitting of each of which requires different numbers of revolutions ofrelative rotation between the needle cylinder and feeders with thefeeders associated with each other in groups of any one of a pluralityof different sizes, wherein said apparatus comprises encoder means forproviding signals which vary with variations in the relative position ofthe needle cylinder and feeders and for providing revolution signalswhich vary with revolutions of relative rotation between the needlecylinder and the feeders, said encoder means includes a first code trackhaving a plurality of zones of a first characteristic and a plurality ofzones of a second characteristic, each of said zones of said first codetrack being of the same longitudinal extent, a second code track havinga plurality of zones of the first characteristic and a plurality ofzones of a second characteristic, each of said zones of a firstcharacteristic of said second code track being of the same longitudinalextent as one of said zones of a first characteristic of said first codetrack and each of said zones of a second characteristic of said secondcode track being of a longitudinal extent which is at least twice asgreat as the longitudinal extent of one of said zones of a secondcharacteristic of said first code track, first reader means forcooperating with each of said zones of the first characteristic of saidfirst code track in turn to provide a signal of a first level duringrelative rotation between the needle cylinder and feeders for a firstpredetermined number of revolutions and for cooperating with each ofsaid zones of the second characteristic of said first code track in turnto provide a signal of a second level during relative rotation betweenthe needle cylinder and feeders for the first predetermined number ofrevolutions, and second reader means for cooperating with each of saidzones of a first characteristic of said second code track in turn toprovide a signal of a first level during relative rotation between theneedle cylinder and feeders for the first predetermined number ofrevolutions and for cooperating with each of said zones of the secondcharacteristic of said second code track in turn to provide a signal ofa second level during relative rotation between the needle cylinder andfeeders for a second predetermined number of revolutions which is atleast twice as great as said first predetermined number of revolutions,control means for receiving signals from said encoder means and foreffecting activation of the needles during relative rotation between theneedle cylinder and feeders, said control means including revolutionregister means activated in response to revolution signals from saidencoder means for providing a series of coded revolution count signalseach of which is indicative of a revolution of relative movement betweenthe needle cylinder and feeders and for sequentially repeating saidseries of coded revolution count signals each time a predeterminednumber of revolutions of relative rotation occurs between the needlecylinder and feeders during operation of the knitting machine,

means for effecting a knitting of a selected one of the plurality ofpatterns each time said series of coded revolution count signals isrepeated by said revolution register means, and selector means forvarying the predetermined number of revolutions required to effect arepetition of said series of coded revolution count signals by saidrevolution register means to enable the knitting machine to knitpatterns requiring different numbers of revolutions of relative rotationbetween the needle cylinder and feeders, said selector means includingswitching means for effecting a transmittal of signals from said firstreader means to said revolution register means during the knitting of apattern requiring a first predetermined number of revolutions ofrelative movement between the needle cylinder and feeders and foreffecting transmittal of signals from said second reader means to saidrevolution register means during the knitting of a pattern requiring asecond predetermined number of revolutions of relative movement betweenthe needle cylinder and feeders.

2. Apparatus as set forth in claim 1 wherein said encoder means furtherincludes means for providing feeder signals which vary as a function ofrelative movement between the needle cylinder and feeders, said controlmeans further including feeder register means activated in response tofeeder signals from said encoder means for providing a series of codedfeeder count signals which are indicative of the feeder in which apredetermined needle on the needle cylinder is located during arevolution of relative movement between the needle cylinder and feeders.

3. A knitting machine for use in knitting a selected one of a pluralityof patterns, said machine comprising a needle cylinder, a plurality ofneedles disposed on said needle cylinder in a circular array whichbegins with a first needle and ends with a last needle, a plurality offeeders disposed about said needle cylinder for feeding strands ofmaterial to said needles, actuator means in each of said feeders foreffecting operation of said needles to knit the strands of material intoa pattern, drive means for effecting relative rotation between saidfeeders and said needle cylinder and for effecting sequentialcooperation between each of said feeders and each of said needles inturn such that each of said feeders is associated in turn with each ofsaid needles on said needle cylinder, encoder means for providingsignals which vary with variations in the relative position of saidneedle cylinder and feeders, said encoder means including first circularcode track means, first reader means cooperating with said firstcircular code track means to provide binary coded feeder signals whichvary with relative movement between said feeders and needle cylinder,second circular code track means distinct from said first circular codetrack means, and second reader means distinct from said first readermeans cooperating with second circular code track means to providebinary coded revolution signals which vary with relative movementbetween said feeders and needle cylinder, control means for receivingsignals from said encoder means and for effecting activation of saidactuator means to knit a pattern during relative movement between saidneedle cylinder and feeders, said control means including feederregister means activated in response to feeder signals from said. firstreader means means for arithmetically operating on said binary codedfeeder signals to provide a series of binary coded feeder count signalsindicative of the particular feeder with which said first needle isassociated during relative rotation between said needle cylinder andfeeders and which binary coded feeder count signals vary in response toachange in the feeder with which said first needle is associated, saidcontrol means including revolution register means activated in responseto said binary coded revolution signals from said second reader meansfor providing a series of coded revolution count signals each of whichis indicative of a revolution of relative movement between the needlecylinder and feeders.

4. A knitting machine as set forth in claim 3 wherein said revolutionregister means includes means for sequentially repeating said series ofcoded revolution count signals each time a predetermined number ofrevolutions of relative rotation occurs between the needle cylinder andfeeders during operation of the knitting machine and a plurality ofcircuit means which are selectively activatable to conduct signals fromsaid plurality of reader means to said revolution register means, foreffecting a knitting of a selected one of the plurality of patterns eachtime said series of coded revolution count signals is repeated by saidrevolution register means, and selector means for varying thepredetermined number of revolutions required to effect a repetition ofsaid series of coded revolution count signals by said revolution countermeans to enable the knitting machine to knit patterns requiringdifferent numbers of revolutions of relative rotation between the needlecylinder and feeders, said selector means including switching means foractivating predetermined combinations of said circuit means to effect arepetition of said series of revolution count signals by said revolutionregister means in a number of revolutions corresponding to a selectedone of the plurality of patterns.

5. A knitting machine for knitting any one of a plurality of differentpatterns, said machine comprising a needle cylinder, a plurality ofspaced apart needles disposed on said needle cylinder and arranged in acircular array extending between a first needle and a last needle, aplurality of feeders disposed about said needle cylinder for feedingstrands of material to said needles, said feeders being associated witheach other in feeder groups comprised of a number of feeders which isvariable to correspond to a selected pattern, drive means for providingrelative movement between said needle cylinder and feeders to enablesaid first needle to be associated with each of said feeders in turn,encoder means for providing signals which vary with relative movementbetween said needle cylinder and feeders, said encoder means includingfirst code track and reader means for providing needle signals whichvary in response to relative movement between said needle cylinder andfeeders by an extent corresponding to the spacing of adjacent needles,second code track and reader means for providing coded feeder signalswhich vary in response to relative movement between said needle cylinderand feeders by an extent which is a function of the spacing of adjacentfeeders, said coded feeder signals being indicative of the feeder withwhich said first needle is associated, and third code track and readermeans for providing coded revolution signals which vary in response torelative movement between said needle cylinder and feeders by an extentwhich is a function of one complete revolution of relative movement,said coded revolution signals being indicative of the number ofrevolutions of relative movement which have occurred between said needlecylinder and feeders during the knitting of a pattern, and control meansfor receiving said needle signals, coded feeder signals, and codedrevolution signals from said encoder means and for effecting activationof said needles during relative rotation between said needle cylinderand feeders, said third code track and reader means including one codetrack having a plurality of zones of a first characteristic and aplurality of zones of a second characteristic, each of said zones ofsaid one code track being of the same longitudinal extent, another codetrack having a plurality of zones of a first characteristic and aplurality of zones of a second characteristic, each of said zones of afirst characteristic of said other code track being of the samelongitudinal extent as one of said zones of said one code track and eachof said zones of a second characteristic of said other code track havinga longitudinal extent which is greater than the longitudinal extent ofone of said zones of a first characteristic of said other code track, afirst reader for cooperating with each of said zones of the firstcharacteristic of said one code track in turn to provide a signal of afirst level during relative rotation between said needle cylinder andfeeders for a first predetermined number of revolutions and forcooperating with each of said zones of the second characteristic of saidone code track in turn to provide a signal of a second level duringrelative rotation between the needle cylinder and feeders for said firstpredetermined number of revolutions, and a second reader for cooperatingwith each of said zones of a first characteristic of said other codetrack in turn to provide a signal of a first level during relativerotation between said needle cylinder and feeders for said firstpredetermined number of revolutions and for cooperating with each ofsaid zones of the second characteristic of said other code track in turnto provide a signal of a second level during relative rotation betweenthe needle cylinder and feeders for a second predetermined number ofrevolutions which is greater than said first predetermined number ofrevolutions, said control means including switching means for enablingsaid control means to utilize signals from said first reader during theknitting of a pattern requiring a first predetermined number ofrevolutions of relative movement between the needle cylinder and feedersand for enabling said control means to utilize signals from said secondreader during the knitting of a pattern requiring a second predeterminednumber of revolutions of relative movement between the needle cylinderand feeders.

1. Apparatus for use in a knitting machine having a needle cylinder holding a plurality of needles to which strands of material are fed from feeders during relative rotation between the needle cylinder and feeders to knit a predetermined one of a plurality of different patterns the knitting of each of which requires different numbers of revolutions of relative rotation between the needle cylinder and feeders with the feeders associated with each other in groups of any one of a plurality of different sizes, wherein said apparatus comprises encoder means for providing signals which vary with variations in the relative position of the needle cylinder and feeders and for providing revolution signals which vary with revolutions of relative rotation between the needle cylinder and the feeders, said encoder means includes a first code track having a plurality of zones of a first characteristic and a plurality of zones of a second characteristic, each of said zones of said first code track being of the same longitudinal extent, a second code track having a plurality of zones of the first characteristic and a plurality of zones of a second characteristic, each of said zones of a first characteristic of said second code track being of the same longitudinal extent as one of said zones of a first characteristic of said first code track and each of said zones of a second characteristic of said second code track being of a longitudinal extent which is at least twice as great as the longitudinal extent of one of said zones of a second characteristic of said first code track, first reader means for cooperating with each of said zones of the first characteristic of said first code track in turn to provide a signal of a first level during relative rotation between the needle cylinder and feeders for a first predetermined number of revolutions and for cooperating with each of said zones of the second characteristic of said first code track in turn to provide a signal of a second level during relative rotation between the needle cylinder and feeders for the first predetermined number of revolutions, and second reader means for cooperating with each of said zones of a first characteristic of said second code track in turn to provide a signal of a first level during relative rotation between the needle cylinder and feeders for the first predetermined number of revolutions and for cooperating with each of said zones of the second characteristic of said second code track in turn to provide a signal of a second level during relative rotation between the needle cylinder and feeders for a second predetermined number of revolutions which is at least twice as great as said first predetermined number of revolutions, control means for receiving signals from said encoder means and for effecting activation of the needles during relative rotation between the needle cylinder and feeders, said control means including revolution register means activated in response to revolutioN signals from said encoder means for providing a series of coded revolution count signals each of which is indicative of a revolution of relative movement between the needle cylinder and feeders and for sequentially repeating said series of coded revolution count signals each time a predetermined number of revolutions of relative rotation occurs between the needle cylinder and feeders during operation of the knitting machine, means for effecting a knitting of a selected one of the plurality of patterns each time said series of coded revolution count signals is repeated by said revolution register means, and selector means for varying the predetermined number of revolutions required to effect a repetition of said series of coded revolution count signals by said revolution register means to enable the knitting machine to knit patterns requiring different numbers of revolutions of relative rotation between the needle cylinder and feeders, said selector means including switching means for effecting a transmittal of signals from said first reader means to said revolution register means during the knitting of a pattern requiring a first predetermined number of revolutions of relative movement between the needle cylinder and feeders and for effecting transmittal of signals from said second reader means to said revolution register means during the knitting of a pattern requiring a second predetermined number of revolutions of relative movement between the needle cylinder and feeders.
 2. Apparatus as set forth in claim 1 wherein said encoder means further includes means for providing feeder signals which vary as a function of relative movement between the needle cylinder and feeders, said control means further including feeder register means activated in response to feeder signals from said encoder means for providing a series of coded feeder count signals which are indicative of the feeder in which a predetermined needle on the needle cylinder is located during a revolution of relative movement between the needle cylinder and feeders.
 3. A knitting machine for use in knitting a selected one of a plurality of patterns, said machine comprising a needle cylinder, a plurality of needles disposed on said needle cylinder in a circular array which begins with a first needle and ends with a last needle, a plurality of feeders disposed about said needle cylinder for feeding strands of material to said needles, actuator means in each of said feeders for effecting operation of said needles to knit the strands of material into a pattern, drive means for effecting relative rotation between said feeders and said needle cylinder and for effecting sequential cooperation between each of said feeders and each of said needles in turn such that each of said feeders is associated in turn with each of said needles on said needle cylinder, encoder means for providing signals which vary with variations in the relative position of said needle cylinder and feeders, said encoder means including first circular code track means, first reader means cooperating with said first circular code track means to provide binary coded feeder signals which vary with relative movement between said feeders and needle cylinder, second circular code track means distinct from said first circular code track means, and second reader means distinct from said first reader means cooperating with second circular code track means to provide binary coded revolution signals which vary with relative movement between said feeders and needle cylinder, control means for receiving signals from said encoder means and for effecting activation of said actuator means to knit a pattern during relative movement between said needle cylinder and feeders, said control means including feeder register means activated in response to feeder signals from said first reader means means for arithmetically operating on said binary coded feeder signals to provide a series of binary coded feeder count signals indicative of the particular feeder wiTh which said first needle is associated during relative rotation between said needle cylinder and feeders and which binary coded feeder count signals vary in response to a change in the feeder with which said first needle is associated, said control means including revolution register means activated in response to said binary coded revolution signals from said second reader means for providing a series of coded revolution count signals each of which is indicative of a revolution of relative movement between the needle cylinder and feeders.
 4. A knitting machine as set forth in claim 3 wherein said revolution register means includes means for sequentially repeating said series of coded revolution count signals each time a predetermined number of revolutions of relative rotation occurs between the needle cylinder and feeders during operation of the knitting machine and a plurality of circuit means which are selectively activatable to conduct signals from said plurality of reader means to said revolution register means, for effecting a knitting of a selected one of the plurality of patterns each time said series of coded revolution count signals is repeated by said revolution register means, and selector means for varying the predetermined number of revolutions required to effect a repetition of said series of coded revolution count signals by said revolution counter means to enable the knitting machine to knit patterns requiring different numbers of revolutions of relative rotation between the needle cylinder and feeders, said selector means including switching means for activating predetermined combinations of said circuit means to effect a repetition of said series of revolution count signals by said revolution register means in a number of revolutions corresponding to a selected one of the plurality of patterns.
 5. A knitting machine for knitting any one of a plurality of different patterns, said machine comprising a needle cylinder, a plurality of spaced apart needles disposed on said needle cylinder and arranged in a circular array extending between a first needle and a last needle, a plurality of feeders disposed about said needle cylinder for feeding strands of material to said needles, said feeders being associated with each other in feeder groups comprised of a number of feeders which is variable to correspond to a selected pattern, drive means for providing relative movement between said needle cylinder and feeders to enable said first needle to be associated with each of said feeders in turn, encoder means for providing signals which vary with relative movement between said needle cylinder and feeders, said encoder means including first code track and reader means for providing needle signals which vary in response to relative movement between said needle cylinder and feeders by an extent corresponding to the spacing of adjacent needles, second code track and reader means for providing coded feeder signals which vary in response to relative movement between said needle cylinder and feeders by an extent which is a function of the spacing of adjacent feeders, said coded feeder signals being indicative of the feeder with which said first needle is associated, and third code track and reader means for providing coded revolution signals which vary in response to relative movement between said needle cylinder and feeders by an extent which is a function of one complete revolution of relative movement, said coded revolution signals being indicative of the number of revolutions of relative movement which have occurred between said needle cylinder and feeders during the knitting of a pattern, and control means for receiving said needle signals, coded feeder signals, and coded revolution signals from said encoder means and for effecting activation of said needles during relative rotation between said needle cylinder and feeders, said third code track and reader means including one code track having a plurality of zones of a first characteristic and a plurality of zones of a second Characteristic, each of said zones of said one code track being of the same longitudinal extent, another code track having a plurality of zones of a first characteristic and a plurality of zones of a second characteristic, each of said zones of a first characteristic of said other code track being of the same longitudinal extent as one of said zones of said one code track and each of said zones of a second characteristic of said other code track having a longitudinal extent which is greater than the longitudinal extent of one of said zones of a first characteristic of said other code track, a first reader for cooperating with each of said zones of the first characteristic of said one code track in turn to provide a signal of a first level during relative rotation between said needle cylinder and feeders for a first predetermined number of revolutions and for cooperating with each of said zones of the second characteristic of said one code track in turn to provide a signal of a second level during relative rotation between the needle cylinder and feeders for said first predetermined number of revolutions, and a second reader for cooperating with each of said zones of a first characteristic of said other code track in turn to provide a signal of a first level during relative rotation between said needle cylinder and feeders for said first predetermined number of revolutions and for cooperating with each of said zones of the second characteristic of said other code track in turn to provide a signal of a second level during relative rotation between the needle cylinder and feeders for a second predetermined number of revolutions which is greater than said first predetermined number of revolutions, said control means including switching means for enabling said control means to utilize signals from said first reader during the knitting of a pattern requiring a first predetermined number of revolutions of relative movement between the needle cylinder and feeders and for enabling said control means to utilize signals from said second reader during the knitting of a pattern requiring a second predetermined number of revolutions of relative movement between the needle cylinder and feeders. 